Today many lamps and lighting systems comprise several light emitters that emit light at different colors and such lamps and lighting systems may be controlled to emit the different colors of light in any possible combination such that about every color of light or about every spectral distribution of light may be emitted. Such lamps or lighting systems are often used to illuminate shelves in a shop or to illuminate a specific object. The lamps of the lighting system may be controlled such that presented products on the shelves or the object appears more appealing to humans. For example, when tomatoes in a supermarket are illuminated with light which comprise a relatively large amount of red light, buyers experience them as an appealing tomatoes.
Published patent application WO2011/092625A1 discloses a method for controlling a color adjustable light source to illuminate an object. In response to receiving a color of the illuminated object, the light source is controlled such that it emits white light in combination with a saturated component corresponding to the color of the illuminated object.
When the system of the published patent application is used, it still uses a relatively large amount of energy. There is a need to make the above lighting systems and lamps more efficient.